Mineral oil composition and improving agent therefor



Patented Apr. 7, 1942 MINERAL OIL COMPOSITION IMPROV- ING AGENT THEREFOR Darwin E. Badertscher, Robert E. Williams, and Henry G. Berger, Woodbury, N. .L, asslgnors to Socony-Vacuum Oil Company, Incorporated, New York, N. Y., a corporation or New York No Drawing.

16 Claims.

This invention has to do in a generalway with viscous mineral oil compositions of the lubricant and'dielectric types which have been improved in one or more of their various properties by having admixed therewith a minor proportion of a mineral oil-improving agent. More specifically, the invention is concerned with the production of a novel class of mineral oil-improving agents and th the production of improved mineral oil compositions of the viscous type containing one or more of these novel improving agents.

It is well known to those familiar with the art that the deteriorating effect of omdatlon and continued use upon a mineral oil fraction manifests itself in various ways, depending upon the source of the oil-that is, the crude from which it is derivedthe refining treatment to which the oil has been subjected, and the particular conditions under which the oil is subjected to oxidation. Motor oils, for example, especially those refined by certain solvent-extraction methods, tend to oxidize when subjected to high temperatures and form products that are corrosive to metal bearings. This corrosive action may be severe with certain bearing metals such as the hard metal alloys .0! the cadmium-silver and copper-lead types, and the class of improving agents contemplated herein are particularly useful as, inhibitors of oxidation and the attending bearing corrosion in oils of this character.

The oil-improving agents contemplated herein also find valuable application in the field of motor-lubrication as inhibitors of the formation of materials which lead, on accumulation, to the sticking of piston rings and the filling of the slots in oil rings. I

Certain of these improving agents are also useful in oils which have been refined for turbine or transformer use. particularly those which have been highly refined, to retard the deterioration Application October 5, 1939, Serial No. 298,052

inhibiting properties mentioned above. the property of improving the pour point of the oil to which they are added.

' The oil-improving agents contemplated herein have as their characterizing constituent a reaction product obtained by reacting a phosphorus pentahalide with an aromatic hydroxycarboxylic acid which we may represent by the general formulae:

R OH

and

R on

R- COOH contemplated herein, may be represented by the.

of such oils and the attending development of 7 acid or sludge which takes place under the 'conditions of use.

Although the general class of compounds or reaction products contemplated herein finds application principally in the field of oxidation inhibitors, and particularly as improving agents for internal combustion engine lubricants, it is to be understood that these improving agents may eflectimprovement in other respects or properties, such as load-carrying capacity, and, as indicated above, certain members of the class, at least, are efiective acid inhibitors for highly refined turbine and transformer oils. In this same connection our invention contemplates, as an especially preferred group or type of improving agents falling within the general class, comreactlon products which are multiunds or w 1. in t they possess in addition to the following equation wherein the ortho-hydroxy acid is used for purposes of illustration:

Because of uncertainty as to the molecular structure of this reaction product we prefer to identify it by its empirical formula CwHrOaClaP or merely as a reaction product instead or indulging in speculation as to the structural formula. It will be observed that in the foregoing illustrative equation and reaction the aromatic hydroxycarboxylic acid used was an unsubstituted ortho-hydroxybenzoic acid (salicylic acid), and while the ortho-hydroxybenzoic acid (both substituted and unsubstituted) and phosphorus pentechloride are considered preferred reactants for obtaining this sub-group of compounds, it is to be understood that the invention includes monoand poly-cyclic aromatic hydroxycarboxylic acids in general and phosphorus pentahalides as initial reactants for btaining this particular group of reaction. products which may be used as oil-improving agents or as initial reactants for obtaining additional improving agents encompassed by the present invention.

As an example of a substituted ortho-hydroxybenzoic acid which may be reacted with a phosphorus pentahalide, we may mention thymotinicacid (methyl isopropyl salicylic acid) having the general formula: I

H HCH .COOH

CHt -CH: H

These two acids, salicylic acid and thymotinic acid, will be used herein to illustrate the manner of synthesizing the various oil-improving agents and to demonstrate their effectiveness in mineral oil compositions.

As has been pointed out above, the reaction products obtained by reacting a phosphorus pentahalide with a monoor poly-cyclic, substituted or unsubstituted aromatic hydroxycarboxylic acid constitute one group of oil-improving agents contemplated by the present invention. Another group of related oil-improving agents is obtained by taking the product of the foregoing reaction as a first reactant and reacting such product with a compound selected from the group consisting of ammonia, organic compounds containing replaceable hydrogen, and compounds containing replaceable metal atoms. Representative of the derivatives from reaction products of the type first mentioned above which are contemplated herein as oil-improving agents are those obtained by reacting the PCls-aromatlc hydroxycarboxylic acid reaction product with materials containing active or replaceable hydrogen atoms, such as: ammonia or amines (compounds having the general formula derivatives of organic acids such as metal carreacting the product thus obtained with an allwlsubstituted hydroxyaromatic compound in which the alkyl substituent is derived from a high molecular weight aliphatic hydrocarbon. For example, a multifunctional oil-improving agent of this type may be obtained by reacting the first reaction product with a wax-phenol obtained by reacting phenol with a chlorinated pcboxylates, thiocarbonates, thiocyanates, cyanides, v

troleum wax in the presence of a Friedel-Crafts catalyst. The details in procedures which may be conveniently followed in synthesizing oil-improving agents of the type contemplated herein, together with further details as to the physical properties and behavior of these reaction products in mineral oil will be best appreciated from the following examples.

EXAMPLE I SYNTHESIS or PGh-Anomarro Oarno-Hrnaoxr Cannoxmo Acm Rasonon Paonucrs (a) PC'ls-salicz/lic acid reaction product (b) PC'ls-thumotinic acid reaction product Following the same procedure described above, equal molecular proportions of thymotinic acid and phomhorus pentachloride were reacted together to yield a brownliquid product which will be hereinafter referred to as Thymotinic-PCla product.

-(c) PC'ls-betahudroxy-alpha-naphthoic acid reaction product Fifteen grams of betahydroxy-alpha-naphthoic acid and 22 grams of P015 were stirred together without external application of heat. A spontaneous reaction occurred, accompanied by a temperature rise from 28 C. to 42 0., forming a dark oil. gl'his was taken up in cc. of

petroleum ether and 10 cc. of benzene and illtered. The solvents were partially removed in a vacuum dessicator, yielding a white crystalline solid with a melting point slightly above room temperature. This product will be identified herein as Hydroxy-naphthoic-PCls product."

The procedure followedin Examples a and b above was essentially that of Anschiitz and Moore, Annalen 239, 314 (1887), and the method described in Example 0 was essentially that of Rab, Ber. 22, 392 (1889).

EXAMPLE II As we have previously pointed out, the products obtained by reacting PC15 with an aromatic ortho-hydroxy carboxylic acid (typified by Examples Ia and 1b above) may be reacted with a compound selected from the group consisting of ammonia, organic compounds containing reactive hydrogen and compounds containing reactive metal atoms, to yield additional oil-improv lng agents within the general class contemplated herein. The following examples illustrate reaction products of this last-mentioned type in which "Salicylic-PO15 product and Thymotinicaavaans PCh products have been reacted with compounds of the type represented by the formula drochloride. The benzene was removed from the filtrate by vacuum'distillation on the water bath. The residue was taken up in petroleum ether. filtered to remove more precipitated amine hydro-chloride, and the product, a dark-colored oil, recovered by vacuum distillation of the petroleum ether on the water bath. The product of this reaction will be hereinafter referred to as "Material from maniple Us.

(b) 'Thymotinic-PCZ; product and monoomulamine In essentially the same manner as in the preceding example, Ho. the product resulting from the reaction of 19.4 grams (0.1 mole) of thymotinic acid and 20.8 grams (0.1 mole) of phosphorus pentachloride was allowed to, react with 60 grams (0.! mole) of monoamylamine. The reactionwas carried out in-petroieum ether instwd of benzene. Otherwise it was analogous to the Example no; the excess amine was, removed by vacuum distillation. The material was a brown. viscous oil weighing 35 grams and will be hereinafter referred to as "Material from Examp e l (cl Salicylic-Pills product" and dibutylamine A solution of 27.5 grams (0.1 mol)"-of the salicylic-Pcls product" in 50 .cc. benzene was added dropwise with stirring to a solution of 77.5 grams (0.6 mol) of dibutylamin'e in 100 cc. benzene during 3 hours. The mixture was-filtered free of amine hydrochloride and the benzene removed by vacuum distillation on the water bath. This residue was freed from the lasttraces of amine hydrochloride by solution a in petroleum ether, filtration and removal of the petroleumn-ether by vacuum distillation. The residue, a brown, moderately viscous oil, weighed 45 gramsr This product analyzed 5.74 per cent phosphorus. 8.81 per cent nitrogen and 0.81 per cent chlorine. Theoretical composition of Cum? is 5.63 per cent phosphorus and 7.82 per cent nitrogen. The product of this reaction will be hereinafter identified as Material from Example IIc.

(a) Salicylic-P171: product and N-amynnam.

product in 50 cc. or benzene was added during 35 minutes to a stirred solution of 50 grams of lw -amylaniline and cc. pyridine in 80 cc. bensens. The temperature rose spontaneously-from 73 to 140.l". After stirring for an additional hour had dropped to 84f F. The filteredfree from hydrochlohour. The cooled, filtered solution was washed with water and dried over anhydrous sodium sulfate. The solvent was removed by vacuum distillation on the hot water bath, leaving as the 5 product 65 grams of a dark red, sticky oil, which will be hereinafter referred to as "Material from mample II (e) "Salicylic-P015 product and crude ricinoleic amine ("Castor amine") A solution of 27.3 grams of salicylic-P61: product" in 50 cc. benzene was added during 20 minutes with stirring to a solution of grams of Castor amine" (crude ricinoleic amine) and 30 cc. of pyridine in 200 cc. of benzene. The reaction was decidedly exothermic. After stirring for 2.5 hours longer the mixture was almost solid because of hydrochloride, which had separated.

About 500 cc. of benzene was added and themixture filtered. The solid was whshed down with more benzene. The combined benzene filtrates were water-washed'and the benzene was removed by vacuum distillation on the hot water bath, leaving a dark red, sticky oil, which will be hereinafter identified as "Material from Example Ilie."

(f) "Salicylic-Pas product" and ammonia This material was prepared in the oil merely by dissolving the calculated amount of "salicylic- PCls product in the oil to be tested, saturating for about an hour with ammonia and filtering oil the precipitated ammoniumchloride. The prodnot of this reaction will be hereinafter referred to as Material from Example 11!."

(g) "Salicylic-Pelt product" and tertiary amyl phenol A mixture of 68.5 grams (0.25 mol) of salicylic-PCls product" and 123 grams (0.75 mol) of "pentaphen" (commercial tertiary amyl phenol) in 150 cc. of benzenewas refluxed for 3 hours until HCl evolution had substantially ceased. The benzene was then removed by vacuum distillation, leaving the product as a dark brown. viscous residue, which will be hereinafter re-' ferred to as Material from'Example 110."

(h) "salic lic-Pct: product and Z-ethul hczanol Thirty-nine grams-of Z-ethyl hexanol and 27.3

without solvent. Immediate reaction ensued, accompanied by a copious evolution of hydrogen chloride. The mixture was heated to C. with stirring and held at" that temperature for 1.5 hours. The mixture was then blown with dry nitrogen gas at 90 C. to free it from occluded HCl and to remove any excess 2-ethy1 hexanol. The product was a straw-yellow;'mobile liquid, and will be hereinafterreferred to as "Material from Example 11h."

(i) Salicylic-P015 product and p-tertiaru cmyl phenol disulflde A mixture of 1 gram of salicylic-PC]: product" and 4.3 grams of p-tertia'ry amyl phenol disulfide was stirred and heated for an hour (until HCl evolution ceased) on a hot water bath. The product was a dark red oil, which will be hereinafter identified as Material from Example II (obtained by Friedel-Crafts condensation of chlorinated paraflin wax and phenol and conride and the dark red filtrate refluxed for an 75 ,tainlns about 0.22 mol of phenolic hydroxyl) and grams of salicylic-Eli product" were mixed fled by filtration.

. only three de water bath, lm a 20 grams of salicylic-PC]: product" .was heated with stirring to 150 1''. and 6 grams of anhydrous aluminum chloride gradually added. Evolution of gaseous HCl started immediately. The mixture was heated with stirring during 30 minutes to a temperature of about 350 F. and was held at that temperature for about 15 minutes. The reaction mixture was cooled, taken up in 250 cc. of benzol and washed with water. The solution was then diluted with petroleum ether and clari- After evaporating to a volume of around 300 cc. and drying with anhydrous sodium sulfate, the solvent was removed by vacuum distillation on a water bath, leaving the product as a dark brown, viscous and tacky residue. This product, which will be hereinafter referred to as "Material from Example 111, is multifunctional in that it v of being an effective pour point depressant for viscous mineral oil fractions in addition to the oxidation-inhibiting property which characterizes the remainder of these oil-improving agents.

(k) Salicylic-P015 product and amvl mercaptan A solution of 27.3 grams of salicylic-PCls product and 33 grams of amyl mercaptan in 100 cc. benzene was stirred and refluxed for 7 days. until the slow HCl evolution had ceased. The solvent was then removed by vacuum distillation on the water bath. The residue was extracted with petroleum ether. Evaporation ofthe'petroleum ether extract yielded a red oil analyzing 5.47 per cent phosphorus, 21.98 per cent sulfur, and 0.57 per cent chlorine. Theoretical composition for CzaHatSsOsP is 6.51 per cent phosphorus, and 20.2 per cent sulfur. This product will be hereinafter identified as "Material from Example Hit."

(1) "Salicylic-Pct; product and potassium ethyl santhate turned dark red in color and a finely divided precipitate (potassium chloride) separated out. The, mixture was filtered when cold. It was noted that the solution was red when viewed through thick layers, but green in a thin layer.- The solution was evaporated under vacuum on a hot water bath, leaving 27 grams of a dark red liquid, which will be identified herein as Material from Example 111.

(m) "Salicylic-H715 product" and potassium thiocyanate A solution of 27.3 I, of the salicylic-P015 product in 70 cc. of benzene was added during 45 minutes to a stirred 1. ion of 29.1 grams potassium thiocw in 150 cc. of e. The temperature of the reaction mixture rose from 80 to 83 F., and the solution colored light brown. After refluxing for an hour the solution e bright red. The mixture was filter-w. The filtrate fumed, indicating the pee of unreacted acid chlorides. More potassium thiocyanate (10 gms.) was added and the ure stirred and refluxed for 1% hours. The mixture was filtered and the henaene removed by vacuum distillation on the hot ell llelgui.

grams, which will be hereinafter identified "Material from Example 11m. F

(n) "Salicylic-P01: product and potassium cyanide To a suspension of 19.5 grams of potassium cyanide in 160 cc. of benzene was added with stirring, during minutes, a solution of 27.8 grams of salicylic-P015 product" in 50 cc. of benzene. The temperature of the reaction mixture rose spontaneously from 80 to 96 F. during the course of the reaction. The mixture was stirred and refluxed for 45 minutes. Some un-'- reacted chloride was still present, so an additional 10 grams of potassium cyanide was added and the refluxing and stirring continued for 2 the property hours. The reaction mixture was then flltered and the solvent removed from the flltrate by (o) "Hydroxwnaphthoic-PCls product and dibutulamine resultant solution washed with dilute hydro-. chloric acid and then with distilled water; After drying over sodium sulfate the petroleum ether was removed by distillation.

IMPROVEMENT OF MINERAL OIL FRACTIONS As was pointed out above, the compounds or react-ice products centemplated here n are efiective to inhibit the corrosive action of mineral oil fractions, such as solventreilned oil, normally corrosive to hard metal alloy bearing metals typified by cadmium-silver and copperlead alloys. In this same regard, our invention contemplates. in addition to mineral oil fractions containing the improving agents contemplated hereln, a method for lubricating alloy bearings which involves the use of a lubricant containing one or more of these improving agents to provide the lubricant film.

v To demonstrate the eil'ectivenes of thehnproving agents contemplated herein as inhibitors 2. of corrosive action of the type above referred to,

1c the alloy samples of motor lubricating oil and oil blends containing representative improving agents were teskd by suspending a 6-gram section of a hard metal alloy bearing in a 30-gram sample of the oil or oil blend and heating same to about C. for 22 hours while bubbling a stream of air against the surface of the bearing. The weight loss in milligrams of the bearing section is interpreted as a measure of the corrosiveness of the oil. In each case, a sample of the oil containing theaddition agent was run concurrently with a sample of the blank oil, and each companion sample contained a bearing section. The results obtained with blends of the various reaction products from the several examples above are listed in Table Ibelow. In all cases, except the test run with Material from pie fie 1: section was from a silver bearing and the oil was a commercial S. A. E. 20 solvent-refined motor oil. The oil containing the product from Example Ila was an S. A. E. 60 acre engine oil, and the bearing section was taken from a copper-lead alloy bearing.

Table I Weiihtlomin Blend Improving agent added to oil g f g Salicylic-P01; roduct Material from xample Ha. Material from Example lIb. Material from Example Ila... Material from Example 11d. r from Example lle wam al from Example IIL Vim-r :11 (mm Example Ila.

Muir-a1 irom Example IIII. Material from Example 111'. Material from Example Ilj.

Material from Example IIn Material irom Example 110 In addition to the foregoing motor oil test, typical improving agents contemplated herein were blended with motor oil and subjected to an accelerated engine operation test to evaluate their ability to prevent ring-sticking, etc., in engine operation. The engine employed in the test was a standard 0. F. R. "knock test engine and the test involved operating the engine first with the oil and then with the oil blend at an approximate speed of 1200 R. P. M. with the throttle set just below detonation, using a compression ratio of 7:1 and a Jacket temperature of 400 F.

The test runs were normally 28 hours in length with an inspection at 14 hours. The following inspections were made: A

I. The piston:

(a) Degrees of ring-sticking being an entirely free ring and 360 a totally stuck ri (b) Per cent of filling of oil slots (c) Deposits (grams) II. Used oil:

(a) Kinematic viscosity (K. V.) at 210 F. (b) Neutralization number (N. N.)

The results obtained are listedin Table ll below, where 011 A1 and "Oil A2" are the motor oil blanks and oils B1 and B2 are the same oil containing 0.5 per cent of the Material from Example 11c" and 1.0 per cent of Material from Example Ila" respectively.

oxidation upon highly refined oils of the type used in turbines, transformers and the like. To demonstrate effectiveness in this regard a very highly acid-refined oil of the transformer type and blends containing same were used. The oil had a specific gravity of 0.871,'a flash point of.

310 F., and a Saybolt Viscosity of 69 seconds at 100 F. The test (known as .a Modified German tar test) was conducted by heating oil samples to 120 C. and bubbling oxygen gas through the oil for a period of '70 hours and then determining the neutralization number of the oilas an indication of the amount of acidic oxidation products formed. Although all of the improving agents tested were effective to inhibit the corrosive action of solvent-refined motor oils and were effective to inhibit ring-sticking in the operation test, some of these same agents failed to show particular promise as inhibitors for highly irefined oils of the turbine and transformer types. Certain of these agents, however, were highly effective in this regard and the results obtained with these products in the test and oil referred to above are listed in Table 1.11 below.

85 The ability of the improving agents contemplated herein to increase the load-carrying capacity of lubricants has been demonstrated with the material from Examples 11c and Ho. An

S. A. E. 60 acre engine oil failed in the Almen test at a load of 4000-6000 pounds at a speed of 200 R. P. M., as compared with a blend of the same oil containing 1.0 per cent of Material from Example 11c, which passed the test at 30,000+pounds. Using a gear oil of 80 to 90 seconds Baybolt viscosity at 210 E, the load limit in the Almen test at a speed of 600 R. P. M. was 4000 pounds and this same 011 containing 5.0 per cent of Material from Example 110" passed the test at 30,000 pounds.

To demonstrate the effectiveness of the preferred multifunctional reaction product (material from Example 119) as a pour point depressant, blends were prepared from a conventional motor lubricating oil having an A. S. T. M. pour test 01' +20 F. A blend of this oil containing only 0.1-per cent of the Materialfrom Example As was also indicated hereinabove, certain of the improving agents contemplated herein are eflective to inhibit the deteriorating effects of Table II Degrees stuck W M 0118 Oil Hours 3%? on A 14 0 o o o o a 5 "Tr i 23 350 o 350 360 90 80. 80 11. 5 29- 94 1. 6 on B 14 o o 0 0 o o o 0 I 23 o 0 0 0 0 0 0 0 10. 5 30- 81 2. 2 on A 14 0 0 90 90 0 40 15 5 23 90 3 0 300 15 50 20 1 22 28- 67 5 on B 14 o o o o 0 Ti 'lr Tr s 25 g o o o 0 Tr Tr Tr 10. 51 2B. 73 1. 45

"Tacky. TIBQB.

119' had a pour point of 10 F., and the same oil containing 1 per cent of this same material had .75 a pourpoint of less than 35 F.; reductions in pour point of 30 and more than 55 respectively.

The amount of improving agents which may be used in the oil will vary more or less with the oil and the conditions of use, but in general the desired improvement can be effected with amounts ranging from about 9.01 per cent to about 10 per cent.

It is to be understood that while we have'herein described certain preferred procedures for synthesizing improving agents of the type con-. tempiated by this invention and have designated certain illustrative reactants which may be employed, the invention is not confined to the specific detailed procedural operations or reactants described but includes within its scope whatever changes fairly come within the spirit of the appended claims.

We claim:

1. An improved mineral oil composition comprising a viscous mineral oil fraction and in admixture therewith a minor proportion of a reaction product obtained by first reacting a phosphorim pentahalide with an aromatic hydroxycarboxylic acid and then reacting the product thus obtained with a compound selected fromthe group consisting of: ammonia, organic compounds containing replaceable hydrogen and compounds containing reactive metal atoms.

2. An improved mineral oil composition comprising a viscous mineral oil fraction and in admixture therewith a minor proportion of a reaction product obtained by first reacting a phosphorus pentachloride with an aromatic orthohydroxycarboxylic acid and then reacting the product obtained from the foregoing reaction with a compound selected from the group conatoms.

4. An improved mineral oil composition comprising a viscous mineraloil fraction and in ad-" mixture therewith a minor proportion of a reaction product obtained by first reacting phosphorus pentachloride with a compound selected from the group having the general formulae:

a a on a coon and - n on a coon in which the R's represent radicals selected from the group consisting of hydrogen, alkyl, arvl. 75

aralkyl, and alkaryl radicals and then reacting lected from the group consisting of ammonia, organic compounds containing replaceable hydrogen atoms and organic compounds containing replaceable metal atoms.

5. An improved mineral oil composition comprising a viscous mineral oil fraction and in admixture therewith a minor proportion of a reaction product obtained by first reacting phos phorus pentachloride with an ortho-hydroxybenzoic acid and then reacting the product thus obtained with an organic compound containing a replaceable hydrogen atom.

6. An improved mineral oil composition com prising a viscous mineral oil fraction and in admixture therewith a minor proportion of areaction product obtained by first reacting phosphorus pentachloride with an ortho-hydroxybenzoic acid and then reacting the product thus obtained with a wax-substituted hydroxyaromatic compound.

7. An improved mineral oil composition comprising a viscous mineral oil fraction and in admixture therewith a minor proportion of a reaction product obtained by first reacting phosphorus pentachloride with an ortho-hydroxybenzoic acid and then reacting the product thus obtained with wax-substituted phenol.

8. The method of lubricating relatively moving metallic bearing surfaces having the corrosion susceptibility of hard metal alloys of the cadmium-silver type which comprises maintaining between the bearing surfaces a lubricant film having as a primary lubricating constituent the combination of a major portion of a mineral oil normally corrosive to alloys of the cadmium-silver type and a minor proportion of a reaction product obtained by first reacting a phosphorus pentachloride with an aromatic ortho-hydroxycarboxylic acid and then reacting the reaction product thus obtained with a compound selected from the group consisting of: ammonia, organic compounds containing replaceable hydrogen atoms and organic compounds containing replaceable metal atoms.

9. A mineral oil-improving agent comprising a reaction product obtained by first reacting a phosphorus pentahalide with an aromatic orthohydroxy-carboxylic acid and then reacting the reaction product thus obtained with a compound selected from the group consisting of ammonia,

organic compounds containing replaceable hydrogen and organic compounds containing replaceable metal atoms.

, 10. A mineral oil-improving agent comprising a reaction product obtained by first reacting phosphorus pentachloride with an hydroxyaromatic' acid selected from the group consisting of acids having the general formulae:

in which the We represent radicals selected from the group consisting of: hydrogen, alkyl, aryl.

aralkyl and alkaryl radicalsnnd then reacting the 7 reaction product thus obtained with a compound selected from the group consisting of ammonia,

organic compounds containing replaceable hydrogen and organic compounds containing replace able metal atoms.

11. A mineral oil-improving agent comp a reaction product obtained by first reacting phosphorus pentachloride with an ortho-hy- "droxybenzoic acid andthen reacting the product thus obtained with an organic compound containing a replaceable hydrogen atom.

13. A mineral oil-improving agent comprising a reaction, product obtained by first reacting phosphorus pentachloride with an ortho-hydroaybenzoic acid and then'reacting the product 1 thus obtained with a wax-substituted hydroxyaromatic compound.

14. An improved mineral oil composition comprising a viscous mineral oil fraction and in admixture therewith a minor proportion of a reaction product obtained by first reacting phosphorus pentachloride with an aromatic hydroxycarboxylic acid and then reacting the product thus obtained with an alcohol.

15. An improved mineral oil composition comprising a viscous mineral oil fraction and in admixture therewith a minor proportion of a reaction product obtained by first reacting phosphorus pentachloride with an aromatic hydroxycarboxylic acid and then reacting the product thus obtained with a mercaptan.

16. An improved mineral oil composition comprising a viscous mineral oil fraction and in admixture therewith a minor proportion of a reaction product obtained by first reacting phosphorus pentachloride with an aromatic hydroxycarboxylic acid and then reacting the product thus obtained with an amine.

DARWIN E. BAnna'rscHER. ROBERT H. HENRY G. BERGER. 

